usb: Add driver for Altus Metrum ChaosKey device (v2)

This is a hardware random number generator. The driver provides both a
/dev/chaoskeyX entry and hooks the entropy source up to the kernel
hwrng interface. More information about the device can be found at
http://chaoskey.org

The USB ID for ChaosKey was allocated from the OpenMoko USB vendor
space and is visible as 'USBtrng' here:

http://wiki.openmoko.org/wiki/USB_Product_IDs

v2: Respond to review from Oliver Neukum <oneukum@suse.de>

 * Delete extensive debug infrastructure and replace it with calls to
   dev_dbg.

 * Allocate I/O buffer separately from device structure to obey
   requirements for non-coherant architectures.

 * Initialize mutexes before registering device to ensure that open
   cannot be invoked before the device is ready to proceed.

 * Return number of bytes read instead of -EINTR when partial read
   operation is aborted due to a signal.

 * Make sure device mutex is unlocked in read error paths.

 * Add MAINTAINERS entry for the driver

Signed-off-by: Keith Packard <keithp@keithp.com>
Cc: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/MAINTAINERS b/MAINTAINERS
index 358eb01..059a9d4 100644 (file)
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -10129,6 +10129,12 @@ S:     Maintained
 F:     drivers/net/usb/cdc_*.c
 F:     include/uapi/linux/usb/cdc.h
 
+USB CHAOSKEY DRIVER
+M:     Keith Packard <keithp@keithp.com>
+L:     linux-usb@vger.kernel.org
+S:     Maintained
+F:     drivers/usb/misc/chaoskey.c
+
 USB CYPRESS C67X00 DRIVER
 M:     Peter Korsgaard <jacmet@sunsite.dk>
 L:     linux-usb@vger.kernel.org

diff --cc drivers/usb/misc/Kconfig
Simple merge

diff --cc drivers/usb/misc/Makefile
Simple merge

diff --cc drivers/usb/misc/chaoskey.c
Simple merge